[PATCH v11 0/1] MR6131: Extend bcp47langs.dll with GetUserLanguages

[Marius Schiffer (＠MariusSchiffer)]

This is an undocumented API used by some programs to
fetch the user's selected languages.

Example is Fusion360 (during its login process).

Signature currently taken from here: https://stackoverflow.com/questions/63877075/what-is-the-right-way-to-get-th...
(Maybe that stackoverflow answer is also why Fusion has implemented this...)

I'm a first-time contributor, please point out if I'm doing anything wrong

--
  v11: bcp47langs: Implement GetUserLanguages()

https://gitlab.winehq.org/wine/wine/-/merge_requests/6131

[PATCH v11 1/1] bcp47langs: Implement GetUserLanguages()

[Marius Schiffer]

From: Marius Schiffer

Implement an undocumented API used by some programs to
fetch the user's selected languages.
Returns current locale.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=56915
---
 configure.ac                       |  1 +
 dlls/bcp47langs/Makefile.in        |  4 +++
 dlls/bcp47langs/bcp47langs.spec    |  2 +-
 dlls/bcp47langs/main.c             | 23 ++++++++++++++
 dlls/bcp47langs/tests/Makefile.in  |  6 ++++
 dlls/bcp47langs/tests/bcp47langs.c | 50 ++++++++++++++++++++++++++++++
 include/Makefile.in                |  1 +
 include/bcp47langs.h               | 35 +++++++++++++++++++++
 8 files changed, 121 insertions(+), 1 deletion(-)
 create mode 100644 dlls/bcp47langs/main.c
 create mode 100644 dlls/bcp47langs/tests/Makefile.in
 create mode 100644 dlls/bcp47langs/tests/bcp47langs.c
 create mode 100644 include/bcp47langs.h

diff --git a/configure.ac b/configure.ac
index 6d093b52526..534ce5cb092 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2467,6 +2467,7 @@ WINE_CONFIG_MAKEFILE(dlls/avifil32/tests)
 WINE_CONFIG_MAKEFILE(dlls/avifile.dll16)
 WINE_CONFIG_MAKEFILE(dlls/avrt)
 WINE_CONFIG_MAKEFILE(dlls/bcp47langs)
+WINE_CONFIG_MAKEFILE(dlls/bcp47langs/tests)
 WINE_CONFIG_MAKEFILE(dlls/bcrypt)
 WINE_CONFIG_MAKEFILE(dlls/bcrypt/tests)
 WINE_CONFIG_MAKEFILE(dlls/bcryptprimitives)
diff --git a/dlls/bcp47langs/Makefile.in b/dlls/bcp47langs/Makefile.in
index 5eb4caaf0e7..dfe10916951 100644
--- a/dlls/bcp47langs/Makefile.in
+++ b/dlls/bcp47langs/Makefile.in
@@ -1,2 +1,6 @@
 MODULE    = bcp47langs.dll
 IMPORTLIB = bcp47langs
+IMPORTS   = combase
+
+SOURCES = \
+	main.c
diff --git a/dlls/bcp47langs/bcp47langs.spec b/dlls/bcp47langs/bcp47langs.spec
index a054c1486a9..969f77b56b8 100644
--- a/dlls/bcp47langs/bcp47langs.spec
+++ b/dlls/bcp47langs/bcp47langs.spec
@@ -48,7 +48,7 @@
 @ stub GetUserDisplayLanguageOverride
 @ stub GetUserLanguageInputMethods
 @ stub GetUserLanguageInputMethodsForUser
-@ stub GetUserLanguages
+@ stdcall GetUserLanguages(long ptr)
 @ stub GetUserLanguagesForAllUsers
 @ stub GetUserLanguagesForUser
 @ stub GetUserLocaleFromLanguageProfileOptOut
diff --git a/dlls/bcp47langs/main.c b/dlls/bcp47langs/main.c
new file mode 100644
index 00000000000..0732aeff581
--- /dev/null
+++ b/dlls/bcp47langs/main.c
@@ -0,0 +1,23 @@
+#include <winstring.h>
+#include "winnls.h"
+
+#include "wine/debug.h"
+
+WINE_DEFAULT_DEBUG_CHANNEL(bcp47langs);
+
+HRESULT WINAPI WINAPI GetUserLanguages(WCHAR delimiter, HSTRING *user_languages)
+{
+    HRESULT hr;
+    WCHAR locale[LOCALE_NAME_MAX_LENGTH];
+
+    if (!user_languages)
+        return E_INVALIDARG;
+    
+    if (!GetUserDefaultLocaleName(locale, LOCALE_NAME_MAX_LENGTH))
+        return E_FAIL;
+
+    if (FAILED(hr = WindowsCreateString(locale, wcslen(locale), user_languages)))
+        return hr;
+
+    return S_OK;
+}
diff --git a/dlls/bcp47langs/tests/Makefile.in b/dlls/bcp47langs/tests/Makefile.in
new file mode 100644
index 00000000000..498e1b34afe
--- /dev/null
+++ b/dlls/bcp47langs/tests/Makefile.in
@@ -0,0 +1,6 @@
+TESTDLL = bcp47langs.dll
+IMPORTS = bcp47langs msvcrt combase
+
+SOURCES = \
+	bcp47langs.c
+
diff --git a/dlls/bcp47langs/tests/bcp47langs.c b/dlls/bcp47langs/tests/bcp47langs.c
new file mode 100644
index 00000000000..a6bdf3ed9e4
--- /dev/null
+++ b/dlls/bcp47langs/tests/bcp47langs.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2025 Marius Schiffer
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <winbase.h>
+
+#include "winstring.h"
+#include "msvcrt/locale.h"
+#include "bcp47langs.h"
+
+#include "wine/test.h"
+
+static void test_GetUserLanguages(void)
+{
+    HSTRING result;
+    const WCHAR *user_languages;
+
+    ok(GetUserLanguages(',', NULL) == E_INVALIDARG, "unknown return code\n");
+
+    setlocale(LC_ALL, "enu");
+    ok(GetUserLanguages(',', &result) == 0, "unknown return code\n");
+    user_languages = WindowsGetStringRawBuffer(result, NULL);
+    ok(!lstrcmpW(user_languages, L"en-US"), "languages=%s\n", debugstr_w(user_languages));
+
+    setlocale(LC_ALL, "deu");
+    ok(GetUserLanguages(',', &result) == 0, "unknown return code\n");
+    user_languages = WindowsGetStringRawBuffer(result, NULL);
+    ok(!lstrcmpW(user_languages, L"de-DE"), "languages=%s\n", debugstr_w(user_languages));
+
+    WindowsDeleteString(user_languages);
+}
+
+START_TEST(bcp47langs)
+{
+    test_get_user_languages();
+}
diff --git a/include/Makefile.in b/include/Makefile.in
index 650d69815f8..694c6f78312 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -45,6 +45,7 @@ SOURCES = \
    axextendenums.h \
    basetsd.h \
    basetyps.h \
+	bcp47langs.h \
    bcrypt.h \
    bdaiface.idl \
    bdaiface_enums.h \
diff --git a/include/bcp47langs.h b/include/bcp47langs.h
new file mode 100644
index 00000000000..4aba6e6195c
--- /dev/null
+++ b/include/bcp47langs.h
@@ -0,0 +1,35 @@
+/*
+ * bcp47langs definitions
+ *
+ * Copyright 2025 Marius Schiffer
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ */
+
+#ifndef _BCP47LANGS_
+#define _BCP47LANGS_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+DWORD WINAPI GetUserLanguages(char delimiter, HSTRING *user_languages);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _BCP47LANGS_ */

[Zhiyi Zhang (＠zhiyi)]

Zhiyi Zhang (@zhiyi) commented about include/bcp47langs.h:
> +/*
> -
> - bcp47langs definitions
> -
> -
> -
> - Copyright 2025 Marius Schiffer
> -
> -

There is no bcp47langs.h in Windows SDK. Let's remove this file and declare the function in tests.

[Zhiyi Zhang (＠zhiyi)]

Zhiyi Zhang (@zhiyi) commented about dlls/bcp47langs/main.c:
> +#include <winstring.h>
> +#include "winnls.h"
> -
>
> +#include "wine/debug.h"
> -
>
> +WINE_DEFAULT_DEBUG_CHANNEL(bcp47langs);
> -
>
> +HRESULT WINAPI WINAPI GetUserLanguages(WCHAR delimiter, HSTRING *user_languages)
> +{

Let's add a FIXME("... stub!\n", ...) here.

[Zhiyi Zhang (＠zhiyi)]

> Let's rename the commit subject to "bcp47langs: Add GetUserLanguages() stub.

This hasn't been addressed.

[Zhiyi Zhang (＠zhiyi)]

Zhiyi Zhang (@zhiyi) commented about dlls/bcp47langs/main.c:
> +#include <winstring.h>
> +#include "winnls.h"
> -
>
> +#include "wine/debug.h"
> -
>
> +WINE_DEFAULT_DEBUG_CHANNEL(bcp47langs);
> -
>
> +HRESULT WINAPI WINAPI GetUserLanguages(WCHAR delimiter, HSTRING *user_languages)

There are two WINAPI here.

[Zhiyi Zhang (＠zhiyi)]

Zhiyi Zhang (@zhiyi) commented about dlls/bcp47langs/tests/bcp47langs.c:
> -
> - Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
> - */
> -
>
> +#include <winbase.h>
> -
>
> +#include "winstring.h"
> +#include "msvcrt/locale.h"
> +#include "bcp47langs.h"
> -
>
> +#include "wine/test.h"
> -
>
> +static void test_GetUserLanguages(void)
> +{
> - HSTRING result;
> - const WCHAR *user_languages;
> -

Let's use a loop and static test data to test it. For example
```
static const struct
{
     const char *locale;
     const WCHAR *expected_languages;
}
tests[] =
{
    {"enu", L"en-US"},
    ...
    add usual locales, for example, English, Chinese, Japanese, Korean, Arabic, French, German.
}

for (int i =0; i < ARRAY_SIZE(tests); i++)
{
     winetest_push_context("%d", i);
     setlocale(LC_ALL, tests[i].locale);
     ok(GetUserLanguages(',', &result) == 0, "unknown return code\n");
     user_languages = WindowsGetStringRawBuffer(result, NULL);
     ok(!lstrcmpW(user_languages, tests[i].expected_languages), "languages=%s\n", debugstr_w(user_languages));
     winetest_pop_context();
}
```

And remember to restore the original locale when the test ends.

[Zhiyi Zhang (＠zhiyi)]

Zhiyi Zhang (@zhiyi) commented about dlls/bcp47langs/tests/Makefile.in:
> +TESTDLL = bcp47langs.dll
> +IMPORTS = bcp47langs msvcrt combase
> -
>
> +SOURCES = \

Please rebase this patch on top of master. The bcp47langs tests are added after MR8448

[Zhiyi Zhang (＠zhiyi)]

You need to fix those CI failures.